With weight reduction, thinning, miniaturization and multi-functionalization of electronic devices, an integration degree thereof increases. Thus, much heat is generated therefrom, and, thus, problems such as malfunction caused by heat. Hence, there is interest and research on the heat release of the electronic devices.
A heat sink is used for heat dissipation. The heat sink may use a principle that when two substances contact each other, the substances distribute heat energy thereof to each other and eventually reach a thermal equilibrium. Thus, the heat sink may receive a strong heat of a heat source and lower the temperature of the heat source. In general, the heat sink is made of aluminum, which has a good thermal conductivity, and is formed into a shape of a fin to maximize a conducting surface area to enable maximum contact with a surrounding air to dissipate the heat by natural convection. However, there is a problem in that it takes a lot of time and cost to fabricate the heat sink. The heat sink may have a heavy weight depending on the metal and a limitation of the surface area size due to manufacturing limitations.
A ceramic foam is widely used as a heat insulating material based on excellent properties of ceramics such as thermal stability, superior mechanical strength, low density, light weight and ability to contain air in pores. However, even with the excellent properties of ceramics and the large surface area thereof, the ceramic foam has not served as the heat dissipating means because of the low thermal conductivity of the ceramic.